(1) Field of the Invention
The present invention relates to a process and an apparatus for disposing of spent sodium sulfur cells through dismantling the sodium sulfur cells.
(2) Related Art Statement
The sodium sulfur cell is a chargeable cell filled with sodium and sulfur inside and outside a solid electrolyte tube made of such as .beta.-alumina, for example. Since the sodium sulfur cell has capacity to store a huge amount of electric power, the cell has attracted public attention as an electric power-storing cell. However, since it is thought that such a cell has a service life of about 10 years, it is anticipated that a large number of spent sodium sulfur cells will exist in the future. However, a technology for disposing of the sodium sulfur cells has not been established, and no apparatus therefor has been developed. Therefore, no conventional technology exists at all against the present invention.
The present inventors have been developing the technology for disposing of the spent sodium sulfur cells, and clarified that in order to dispose of the sodium sulfur cell, it is necessary to form an opening in the cell by cross-cutting the cell, recovering sodium from the interior of the cell through the opening, and extracting a metallic inner tube from an outer tube in a multiple-tube structure of the cell. However, it was discovered that since both the inner and outer tubes are thin and long and since sodium, etc. exist between the tubes, the inner tube cannot be extracted from the outer tube if their axes are deviated from each other even slightly, and that it is not easy to automatically effect such an extracting work. Furthermore, although the inner tubes can be extracted from the outer tubes by checking the sodium sulfur cells one by one and aligning the inner and outer tubes, a long time is necessary to dispose of one cell, which makes it impossible to dispose of a large number of the cells.
The present invention is to solve the above problems possessed by the above art, and to provide a process and an apparatus for disposing of sodium sulfur cells, which can simultaneously and automatically recover sodium and extract inner tubes from a plurality of the sodium sulfur cells.